Ramayana
सो ऽहं निमित्ते कस्मिंश्चिद्विज्ञातायुर्द्विजोत्तम । कालधर्मं हृदि न्यस्य ततो वनमुपागमम् ॥ 7-78-7 ॥
Then I, O best of the twice-born, having through a certain sign come to know the span of my life, set the law of death within my heart and thereupon withdrew to the forest.
english translation